Bad blood has run through the New York ice cream trade for decades. In 1969, a Mister Softee driver was kidnapped by rivals who blew up his truck. In 2004, a cone-selling couple in their 60s were ambushed by competitors who beat them into critical condition with a wrench. In a 2010 brawl caught on video, two drivers near Columbus Circle exchanged punches before one man pushed the other’s face into a planter.